Just got my 2011 4CS cabriolet delivered after waiting more than a week for it to be shipped from New Jersey to Texas.

I took it for a long drive and I noticed a steady fan-type blowing noise coming from the engine in the back, which stops when the car ignition is turned off. Is this the normal engine sound that is always heard? It seems louder than I recall from test driving other 997 cabs.

 

Sometimes when I get home from a long drive and it's hot in the garage that fan comes on all by itself and is normal. Once the engine temp cools it will turn off. During operation of the engine it's on and is normal...you just didn't notice because you were test driving..now you own it! EVERY little sound will be heard by you!! LOL

 

Wait until you start pushing it and the front blowers come on.

 

I'm in Texas too and I haven't noticed the rear fan come on during the last many weeks or even months. It's been fairly cool for quite a while. I've only noticed the rear fan running on much hotter days (85+) and even then it doesn't seem to stay on for very long. Note that on really hot days it can even keep running or come on after the engine is turned off and the key removed.

Please excuse a possibly dumb question... but are you sure it is the rear fan... you've heard it from outside the car? On my 2006, one of the front fans failed and this apparently triggers a fail-safe where the other front fan comes on full blast most of the time. It makes quite the roar but I only correctly placed it after getting out of the car with it running.

If the rear fan is still blowing on full even when the car is still cool, such as just after startup, then the thermostat it uses or the relay that turns it on may have failed. At least you still have full warranty available if there is a problem.

 

Yes it is the rear fan. This evening, I drove the car to dinner and the fan did not come on because we only drove about 5 minutes. It took about 20-30 minutes for it to come on earlier today. The temperature outside was about 70 degrees here in Houston.

 

I've got an 06 cab and I notice mine's on most of the time- I'm in Nor Cal so definitely not as hot as Houston gets, but when the temps are above 70 outside, I do notice it more.

Perfect excuse to upgrade or mod your exhaust...

 

yup.. normal when the engine is still trying to cool off. I'll shut the car off and then come back later and the fan is blowing. Surprised me the first time it happened. Usually only happens to me during hot days in the summer.

 

JRW
Do you still have the issue of the blower fan coming on? Were you able to get an answer as to whether its operating normally or not? I have a 08 C4 and the blower fan comes on even when cold start in the morning.

 

Mine is on, always, often, forever it seems. Used to it by now. No changes to temp. guage.

 

PoundCake, Did you ever have Porsche or anyone look at it and advise you that it is normal or not? Porsche tells me this is normal for a 997-1. I have my doubts.

 

No, it bothered me at first but now used to it.